Source Acknowledgments
Last updated: 2026-05-24
Every Premium Learning Path on Learning Whistle is built on a foundation of 43 authoritative open-access sources. This page acknowledges every library, archive, repository, controlled-vocabulary authority, and data source The Conductor's Ledger draws from, with full attribution and license terms.
Of these sources, 24 require explicit attributionunder their open-source licenses. This page satisfies that attribution obligation platform-wide. Where individual sources appear in your path, you'll also see per-source citation cards.
How to read this page
Sources are grouped by what they provide, not by where they come from. Each entry shows:
- Name — the source as it should be referred to
- License — the legal terms under which we use the source
- Terms of Use — a direct link to the source's canonical terms
- Attribution — the suggested attribution text (where required)
- What it provides — a brief description
Reference & Knowledge Graphs (2)
Wikidata (SPARQL)
Structured knowledge graph; entity resolution, Q-ID lookup, instance/subclass/field traversal
License: CC0 (Public Domain Dedication)
Terms of Use: https://www.wikidata.org/wiki/Wikidata:Licensing
Wikipedia (REST API + Parse API)
First-paragraphs fetch for topical mapping; See-also expansion
License: CC BY-SA 4.0
Terms of Use: https://en.wikipedia.org/wiki/Wikipedia:Reusing_Wikipedia_content
Attribution: “Content adapted from Wikipedia under CC-BY-SA 4.0”
Citation Graphs (1)
OpenCitations COCI
Citation graph traversal; required for L4 citation-chase lane in the Conductor's Ledger
License: CC0 (Public Domain Dedication)
Terms of Use: https://opencitations.net/index/coci
Peer-Reviewed Research (4)
SciELO ArticleMeta
Latin American open-access journals
License: BSD-2-Clause (API); CC-BY (most content)
ArticleMeta library is BSD-2-clause; content is mostly CC-BY OA but verify per-item
Terms of Use: https://scielo.org/en/about-scielo/open-access-statement/
Attribution: “Source: SciELO (CC-BY)”
ChEMBL
Chemistry and pharmacology bioactivity data; complements PubChem
License: CC BY-SA 3.0
Compound property calculations derived from commercial software may have separate licensing — verify per-calculation type
Terms of Use: https://chembl.gitbook.io/chembl-interface-documentation/about
Attribution: “Source: ChEMBL, EMBL-EBI (CC-BY-SA 3.0)”
Zenodo
CERN-operated cross-disciplinary research artifacts — datasets, software, posters, theses. Complements arXiv/EuropePMC/OpenAlex. Especially strong for CS/AI (ML model cards), Physics datasets, Biology.
License: mixed (per-deposit)
Per-deposit — every CC variant + custom licenses. Filter strictly on CC0/CC-BY/CC-BY-SA without NC. Zenodo metadata exposes license cleanly.
Terms of Use: https://about.zenodo.org/terms/
Attribution: “Source: Zenodo (per-item license)”
OpenAIRE Graph
European-heavy OA discovery + funding linkage aggregator; great for EU policy/sociology/health research surfaces.
License: CC BY 4.0
OpenAIRE Graph itself is CC-BY 4.0 (explicit, verified). Commercial use permitted with attribution. Use this NOT BASE — BASE metadata is CC-BY-NC.
Terms of Use: https://www.openaire.eu/data-policies
Attribution: “Source: OpenAIRE Research Graph (CC-BY 4.0)”
Preprint Servers (2)
bioRxiv
Life-sciences preprints
License: CC0 (Public Domain Dedication)
API metadata is CC0; per-preprint full text licenses vary (often CC-BY or CC-BY-NC; check per-paper)
Terms of Use: https://www.biorxiv.org/about-biorxiv
medRxiv
Medical preprints
License: CC0 (Public Domain Dedication)
API metadata is CC0; per-preprint full text licenses vary
Terms of Use: https://www.medrxiv.org/about-medrxiv
Government Reports & Publications (8)
Federal Register
Daily federal agency notices, proposed and final rules
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.federalregister.gov/reader-aids/legal-information/disclaimer
GovInfo.gov (GPO)
Canonical US federal document warehouse — congressional hearings, GAO reports, Presidential papers, US Code historical versions, CFR historical, Budget of the US, Statutes at Large. Sits beneath congress.gov / Federal Register / eCFR and exposes 40+ additional collections.
License: Public Domain (US gov work, 17 U.S.C. §105)
Uses the shared api.data.gov key (already in Secret Manager).
Terms of Use: https://www.govinfo.gov/about/policies
CRS Reports (Congressional Research Service)
Non-partisan, citation-rich 5-30 page policy primers written by subject-matter PhDs. Map nearly 1:1 to Learning Whistle Station format at undergrad-to-graduate reading level.
License: Public Domain (US gov work, 17 U.S.C. §105)
No formal API; EveryCRSReport.com mirrors with structured metadata. Bulk scraping permitted.
Terms of Use: https://crsreports.congress.gov/about
GAO Reports
Independent non-partisan analyses of federal programs; case studies in business contracting, economics, political science, medicine, engineering procurement.
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.gao.gov/about/website-policies
Oversight.gov (Federal Inspectors General)
Aggregates 70+ federal Inspector General reports across all agencies. Unique investigative case-study source most retrieval tools miss entirely.
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.oversight.gov/about
SEC EDGAR
10-K narratives, MD&A sections, IPO S-1 prospectuses. Real-world business case studies — extraordinary teaching material for Business & Entrepreneurship and Economics & Finance.
License: Public Domain (US gov work, 17 U.S.C. §105)
Filings are submitted by registrants but SEC publishes as public record with no restriction on republication. Standard practice across financial education. Must send User-Agent header identifying app + email.
Terms of Use: https://www.sec.gov/about/data
GOV.UK Content API
UK government explainers on every policy topic; microlearning format. Categories: Political Science, Law, Economics, Medicine (NHS guidance), Education.
License: OGL-3.0
UK Open Government Licence v3.0 — functionally equivalent to CC-BY 4.0; explicitly permits commercial use with attribution.
Terms of Use: https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
Attribution: “Contains public sector information licensed under the Open Government Licence v3.0”
EU Open Data Portal (data.europa.eu)
EU-wide data and publications across all policy domains. Categories: Economics, Political Science, Law (EU directives).
License: CC BY 4.0
Most items under CC-BY 4.0 or equivalent; per-item license metadata available — filter strictly. EU Commission default since 2011 is the Commission Reuse Decision (functionally CC-BY).
Terms of Use: https://data.europa.eu/en/about/policies-and-procedures
Attribution: “Source: EU Open Data Portal”
Statistical & Economic Data (5)
FRED (Federal Reserve Economic Data)
US and international economic time series
License: Public Domain (US gov work, 17 U.S.C. §105)
Per FRED terms; commercial use permitted with attribution where source data permits
Terms of Use: https://fred.stlouisfed.org/legal/
Attribution: “Source: Federal Reserve Bank of St. Louis (FRED)”
BLS (Bureau of Labor Statistics)
US labor market statistics
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.bls.gov/bls/linksite.htm
US Census API
US Census data; population, housing, economic
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.census.gov/about/policies/open-gov/open-data.html
USAspending.gov
Concrete federal spending examples — what specific agencies actually bought in specific quarters. Powers case-study slot for Economics, Political Science, Business stations.
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.usaspending.gov/about
Our World in Data
Visualizable global indicators across nearly every Learning Whistle category. Highest-ROI integration alongside GDELT per data journalist.
License: CC BY 4.0
OWID-derived datasets in their GitHub repo are CC-BY 4.0. Upstream sources have their own licenses but the OWID processed CSVs are CC-BY.
Terms of Use: https://ourworldindata.org/about
Attribution: “Data: Our World in Data (CC-BY 4.0)”
Standards & Specifications (2)
Electronic Code of Federal Regulations
Actual federal regulations (not bills); US gov work
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.ecfr.gov/about
EUR-Lex
EU treaties, directives, regulations, ECJ case law. Categories: Law & Jurisprudence, Political Science.
License: EU-Commission-Reuse-Decision
EU Commission Reuse Decision permits commercial reuse with source attribution; functionally equivalent to CC-BY. Free registration for web service.
Terms of Use: https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
Attribution: “© European Union, EUR-Lex”
Open Wiki Textbooks (1)
Wikibooks
Open textbook content; complements OpenStax for topics OpenStax doesn't cover
License: CC BY-SA 4.0
Also dual-licensed under GFDL for some content
Terms of Use: https://en.wikibooks.org/wiki/Wikibooks:Copyrights
Attribution: “Material from Wikibooks under CC-BY-SA 4.0”
Instructional & Educational Media (3)
Wikiversity
Educational resources organized by learning module; full pedagogical scaffolding
License: CC BY-SA 4.0
Terms of Use: https://en.wikiversity.org/wiki/Wikiversity:Copyrights
Attribution: “Material from Wikiversity under CC-BY-SA 4.0”
NASA Space Place
K-6 STEM explainer content; public domain US government work
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.nasa.gov/multimedia/guidelines/index.html
USGS Education
K-6 earth-science explainer content; public domain US government work
License: Public Domain (US gov work, 17 U.S.C. §105)
Terms of Use: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits
Primary Historical Sources (3)
NYPL Digital Collections
Primary historical sources, US humanities focus
License: mixed (per-item)
Per-item license; PD subset is large
Terms of Use: https://digitalcollections.nypl.org/about/rights
Attribution: “Source: The New York Public Library Digital Collections”
EEBO-TCP Phase I
25,000 TEI-encoded early modern English books (1473-1700). Shakespeare contemporaries, Reformation pamphlets, early scientific revolution, English Civil War. Crown jewel of open digital humanities.
License: CC0 (Public Domain Dedication)
Phase I released to public domain January 2015. Phase II still restricted, rolling release. Use Phase I bulk only.
Terms of Use: https://textcreationpartnership.org/about-the-tcp/eebo-tcp/
Founders Online (NARA)
~185,000 documents — Washington, Adams, Jefferson, Madison, Hamilton, Franklin papers. Founding-era American political thought primary sources.
License: Public Domain (US gov work, 17 U.S.C. §105)
"No known copyright restrictions" per NARA — effectively public domain for the documents and site presentation.
Terms of Use: https://founders.archives.gov/about
Wiki Primary Texts (1)
Wikisource
Historical primary texts, speeches, original documents
License: PD (majority) + CC-BY-SA-4.0
Wikisource policy prohibits NC-licensed works, which simplifies the per-item check
Terms of Use: https://en.wikisource.org/wiki/Wikisource:Copyright_policy
Attribution: “Text from Wikisource (public domain or CC-BY-SA 4.0)”
Cultural Heritage & Museums (2)
Deutsche Digitale Bibliothek
German digital library; broad cultural-heritage coverage
License: CC0 (metadata); per-item content licenses vary
Metadata CC0; check dcterms:rights on each item for content reuse
Terms of Use: https://www.deutsche-digitale-bibliothek.de/content/api-nutzungsbedingungen?lang=en
Attribution: “Source: Deutsche Digitale Bibliothek”
DPLA (Digital Public Library of America)
US digital library aggregator across many institutions
License: mixed (per-item via providers)
DPLA aggregates from many providers; check rights statement per item
Terms of Use: https://dp.la/about/policies
Attribution: “Source: Digital Public Library of America”
Controlled Vocabularies & Authority Files (1)
Getty Vocabularies (AAT/ULAN/TGN)
Art-historical controlled vocabularies (AAT), artist names (ULAN), geographic names (TGN); commercial-friendly authority data
License: ODC-By 1.0
Terms of Use: https://www.getty.edu/research/tools/vocabularies/license.html
Attribution: “Contains information from Art & Architecture Thesaurus (AAT)® made available under the ODC Attribution License”
Dictionaries & Quotation Collections (2)
Wiktionary
Definitions, etymology, IPA pronunciations; complements MeSH/LCSH/AAT for general-vocabulary topics in Round 0
License: CC BY-SA 4.0
Terms of Use: https://en.wiktionary.org/wiki/Wiktionary:Copyrights
Attribution: “Definitions from Wiktionary under CC-BY-SA 4.0”
Wikiquote
Quotations, speeches, sayings; strong primary-artifact source
License: CC BY-SA 4.0
Terms of Use: https://en.wikiquote.org/wiki/Wikiquote:Copyrights
Attribution: “Quotations from Wikiquote under CC-BY-SA 4.0”
Web Archives (1)
Wayback Machine CDX
Archived practitioner web content with stable provenance URLs
License: archive-snapshots
Snapshots are linkable, NOT redistributable. The Wayback link IS the citation; do not re-host content.
Terms of Use: https://archive.org/about/terms.php
Attribution: “Archived via the Internet Archive Wayback Machine”
Bulk Datasets (5)
Wikidata (bulk dumps)
Weekly full corpus dumps in JSON/RDF/XML; alternative to SPARQL for offline lookups
License: CC0 (Public Domain Dedication)
Terms of Use: https://www.wikidata.org/wiki/Wikidata:Licensing
Google Books Ngrams (standard)
Word-frequency analysis for linguistic and historical topics
License: CC BY 3.0
Standard dataset only. Syntactic ngrams variant is CC-BY-NC-SA — do NOT use.
Terms of Use: https://books.google.com/ngrams/info
Attribution: “Data from Google Books Ngrams Viewer, CC-BY 3.0”
OpenStreetMap (planet dump)
Geographic features; useful for geographic / urban / transportation topics
License: ODbL 1.0
Share-alike applies to derivative DATABASES, not necessarily to derivative works. Safe for prose ingestion + citation; risky if Learning Whistle ever exposes a derived OSM dataset via its own API.
Terms of Use: https://www.openstreetmap.org/copyright
Attribution: “© OpenStreetMap contributors, ODbL”
GDELT Project
Global events 1979→present, 15-minute updates. Location/sentiment/actor-tagged. Transforms Conductor's Ledger from static-knowledge engine into "what actually happened this week" grounding.
License: GDELT-permissive
GDELT-specific terms — free for any use including commercial, with attribution required to GDELT Project. Available via BigQuery public dataset (already in GCP).
Terms of Use: https://www.gdeltproject.org/about.html#termsofuse
Attribution: “Data from the GDELT Project”
ICIJ Offshore Leaks Database
Panama/Paradise/Pandora Papers entity database. Premium-tier differentiator for Law, Political Science, Economics stations — phenomenal case-study material on real-world tax structures.
License: ODC-By 1.0
Terms of Use: https://offshoreleaks.icij.org/pages/about
Attribution: “Source: International Consortium of Investigative Journalists (ICIJ) Offshore Leaks Database (ODC-By)”
Notes on Licensing
Public Domain & CC0
A substantial portion of our sources are public domain — either by virtue of being authored by the US federal government (PD by 17 U.S.C. §105), or by explicit dedication under the Creative Commons CC0 Public Domain Dedication. These sources can be freely used for any purpose with or without attribution.
Creative Commons Attribution (CC-BY)
Many of our sources are licensed under CC-BY 3.0 or 4.0, which permits commercial use with proper attribution. We satisfy that attribution by listing the source on this page and on per-source citation cards within the relevant learning paths.
Share-Alike Licenses (CC-BY-SA, ODbL)
A smaller set of sources — primarily the Wikimedia family (Wikipedia, Wiktionary, Wikiquote, Wikiversity, Wikibooks, Wikisource) — are licensed under CC-BY-SA, which requires share-alike on derivative works. We satisfy this by paraphrasing rather than reproducing substantial verbatim text, and by clearly attributing the source. OpenStreetMap data is ODbL, with similar share-alike implications for derivative databases (which we do not produce or expose).
Per-Item License Sources
Some aggregator sources (DDB Germany, NYPL, DPLA, SciELO, Zenodo) contain items with varying per-item licenses. Our Conductor's Ledger pipeline performs per-item license verification at retrieval time; items with non-commercial licenses are excluded from premium-path generation.
What we deliberately don't use
We've excluded several otherwise excellent academic and humanities sources because their licenses prohibit commercial use, even by educators using a paid platform. This means our coverage of certain areas (particularly pre-modern non-Western humanities) is intentionally thinner than it could be. When this affects a specific path, the Conductor's Ledger surfaces a scope note so you know what we could and couldn't source.
Questions about source use
If you represent one of the sources listed here and have questions about our use, or if you spot an attribution we've gotten wrong, please reach out to learn@learningwhistle.com. We take our obligations to the open-source community seriously and will respond promptly.
See also: our methodology page for the full pipeline that connects these sources to your learning path.